Cannabinoid therapy in epilepsy.

 Image result for curr opin neurol“To review the history, pharmacology, and clinical science of cannabidiol (CBD) in the treatment of epilepsy.

RECENT FINDINGS:

Phase III randomized controlled trials and prospective open label trials have provided efficacy and safety data for the use of CBD in pediatric onset severe epilepsies. The product that was studied in the vast majority of these published trials, Epidiolex (>99% of CBD and <0.10% Δ9-tetrahydrocannabinol (THC); GW pharmaceuticals, Cambridge, UK), has now been FDA approved based on this published data.

SUMMARY:

Identification of CBD, Δ9-THC, and the endocannabinoid system in the mid-20th century has led to advancement of cannabis-based therapies for epilepsy. Based on clinical trial data, Epidiolex is the first CBD medication approved by a national regulatory agency (US Food and Drug Administration for Dravet and Lennox Gastaut syndrome; European Medicines Agency for Lennox Gastaut syndrome). Approval of CBD as a treatment for these rare and severe pediatric-onset epilepsy syndromes is an important milestone, but the complete spectrum of use of cannabis-derived products, and the use of CBD for other epilepsy syndromes remains to be determined.”

https://www.ncbi.nlm.nih.gov/pubmed/30676535

Epidiolex (Cannabidiol): A New Hope for Patients With Dravet or Lennox-Gastaut Syndromes.

 SAGE Journals

“OBJECTIVE: To review the efficacy, safety, pharmacology and pharmacokinetics of pure, plant-derived cannabidiol (CBD; Epidiolex) in the treatment of Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS).

DATA SYNTHESIS: Pure, plant-based CBD is a pharmaceutical grade extract that exhibits clinically significant antiseizure properties, with a hypothesized multimodal mechanism of action. In the GWPCARE trial series, CBD displayed superior efficacy in reducing key seizure frequencies (convulsive seizures in DS; drop seizures in LGS) by 17% to 23% compared with placebo as adjunctive therapy to standard antiepileptic drugs in patients 2 years of age and older. Common adverse effects were somnolence, diarrhea, and elevated hepatic transaminases. Noteworthy drug-drug interactions included clobazam, valproates, and significant inducers/inhibitors of CYP2C19 and 3A4 enzymes.

Relevance to Patient Care and Clinical Practice: A discussion regarding CBD dosing, administration, adverse effects, monitoring parameters, and interactions is provided to guide clinicians. CBD offers patients with DS and LGS a new treatment option for refractory seizures.

CONCLUSION:

This is the first cannabis-derived medication with approval from the US Food and Drug Administration. This CBD formulation significantly reduces seizures as an adjunct to standard antiepileptic therapies in patients ≥2 years old with DS and LGS and is well tolerated.”

https://www.ncbi.nlm.nih.gov/pubmed/30616356

https://journals.sagepub.com/doi/abs/10.1177/1060028018822124?journalCode=aopd

“Why marijuana is headed for the mainstream. The credibility of cannabis as a source of a legitimate pharmaceutical ingredient in prescription medications took a major step forward in 2018 when the FDA approved Epidiolex (cannabidiol) for two types of severe seizures. Epidiolex was a stellar candidate for approval. It reduced convulsive seizures by about 40% and has a good safety profile.”  https://www.ncbi.nlm.nih.gov/pubmed/30620324

Long-Term Safety, Tolerability, and Efficacy of Cannabidiol in Children with Refractory Epilepsy: Results from an Expanded Access Program in the US.

“Purified cannabidiol is a new antiepileptic drug that has recently been approved for use in patients with Lennox-Gastaut and Dravet syndromes, but most published studies have not extended beyond 12-16 weeks.

The objective of this study was to evaluate the long-term safety, tolerability, and efficacy of cannabidiol in children with epilepsy.

  Twenty-six children were enrolled. Most had genetic epilepsies with daily or weekly seizures and multiple seizure types. All were refractory to prior antiepileptic drugs (range 4-11, mean 7), and were taking two antiepileptic drugs on average. Duration of therapy ranged from 4 to 53 months (mean 21 months). Adverse events were reported in 21 patients (80.8%), including reduced appetite in ten (38.4%), diarrhea in nine (34.6%), and weight loss in eight (30.7%). Four (15.4%) had changes in antiepileptic drug concentrations and three had elevated aspartate aminotransferase and alanine aminotransferase levels when cannabidiol was administered together with valproate. Serious adverse events, reported in six patients (23.1%), included status epilepticus in three, catatonia in two, and hypoalbuminemia in one. Fifteen patients (57.7%) discontinued cannabidiol for lack of efficacy, one because of status epilepticus, and one for severe weight loss. The retention rate declined rapidly in the first 6 months and more gradually thereafter. At 24 months, the number of patients continuing cannabidiol as adjunctive therapy was nine of the original 26 (34.6%). Of these patients, seven (26.9%) had a sustained > 50% reduction in motor seizures, including three (11.5%) who remain seizure free.

CONCLUSION:

Over a 4-year period, cannabidiol was effective in 26.9% of children with otherwise refractory epilepsy. It was well tolerated in about 20% of patients, but 80.8% had adverse events, including 23.1% with serious adverse events. Decreased appetite and diarrhea were frequent along with weight loss that became evident only later in the treatment.”
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